document.addEventListener('DOMContentLoaded', function() {
    const linksList = document.getElementById('links-list');
    const modal = document.getElementById('link-modal');
    const deleteModal = document.getElementById('delete-modal');
    const form = document.getElementById('link-form');
    const searchInput = document.getElementById('search-input');
    const queryInput = document.getElementById('query-input');
    const simpleBtn = document.getElementById('simple-search-btn');
    const queryBtn = document.getElementById('query-search-btn');
    const saveCollectionBtn = document.getElementById('save-collection-btn');
    const saveCollectionModal = document.getElementById('save-collection-modal');
    const saveCollectionForm = document.getElementById('save-collection-form');
    let deleteTargetId = null;
    let searchMode = 'simple';
    let lastQuery = '';
    let lastResults = [];

    function setSearchMode(mode) {
        searchMode = mode;
        simpleBtn.classList.toggle('active', mode === 'simple');
        queryBtn.classList.toggle('active', mode === 'query');
        searchInput.style.display = mode === 'simple' ? '' : 'none';
        queryInput.style.display = mode === 'query' ? '' : 'none';
        searchInput.placeholder = mode === 'simple'
            ? 'Search links by title, URL, tags, or notes...'
            : 'e.g. personal AND lan NOT ai';
    }

    simpleBtn.addEventListener('click', () => setSearchMode('simple'));
    queryBtn.addEventListener('click', () => setSearchMode('query'));

    async function loadLinks(search = '') {
        try {
            let links;
            if (searchMode === 'query' && search) {
                lastQuery = search;
                const data = await LinkSync.previewQuery(search);
                if (data.error) {
                    linksList.innerHTML = `<div class="empty-state"><p>Query error: ${escapeHtml(data.error)}</p></div>`;
                    lastResults = [];
                    return;
                }
                links = data.results || [];
            } else {
                lastQuery = '';
                links = await LinkSync.getLinks(search ? { search } : {});
            }
            lastResults = Array.isArray(links) ? links : [];
            renderLinks(lastResults);
        } catch (err) {
            linksList.innerHTML = `<div class="empty-state"><p>Failed to load links: ${err.message}</p></div>`;
            lastResults = [];
        }
    }

    function renderLinks(links) {
        if (!links || links.length === 0) {
            linksList.innerHTML = '<div class="empty-state"><p>No links found.</p><button class="btn btn-primary" id="empty-add-btn">+ Add your first link</button></div>';
            document.getElementById('empty-add-btn').addEventListener('click', openModal);
            return;
        }

        linksList.innerHTML = `
            <div class="data-table">
                <table>
                    <thead>
                        <tr>
                            <th>Title</th>
                            <th>URL</th>
                            <th>Tags</th>
                            <th>Created</th>
                            <th>Actions</th>
                        </tr>
                    </thead>
                    <tbody>
                        ${links.map(link => `
                            <tr>
                                <td>${escapeHtml(link.title)}</td>
                                <td class="truncate"><a href="${escapeHtml(link.url)}" target="_blank" class="link-url">${escapeHtml(link.url)}</a></td>
                                <td><div class="tags">${(link.tags || []).map(t => `<span class="tag">${escapeHtml(t)}</span>`).join('')}</div></td>
                                <td>${formatDate(link.created_at)}</td>
                                <td class="actions">
                                    <button class="btn-icon" data-action="edit" data-id="${link.id}" title="Edit">&#9998;</button>
                                    <button class="btn-icon" data-action="delete" data-id="${link.id}" title="Delete">&#128465;</button>
                                </td>
                            </tr>
                        `).join('')}
                    </tbody>
                </table>
            </div>
        `;

        linksList.querySelectorAll('[data-action="edit"]').forEach(btn => {
            btn.addEventListener('click', () => editLink(btn.dataset.id));
        });
        linksList.querySelectorAll('[data-action="delete"]').forEach(btn => {
            btn.addEventListener('click', () => confirmDelete(btn.dataset.id));
        });
    }

    function openModal(link = null) {
        document.getElementById('modal-title').textContent = link ? 'Edit Link' : 'Add Link';
        document.getElementById('link-id').value = (link && link.id) ? link.id : '';
        document.getElementById('link-url').value = link ? link.url : '';
        document.getElementById('link-title').value = link ? link.title : '';
        document.getElementById('link-description').value = link ? (link.description || '') : '';
        document.getElementById('link-notes').value = link ? (link.notes || '') : '';
        document.getElementById('link-tags').value = link ? (link.tags || []).join(', ') : '';
        document.getElementById('link-favicon').value = link ? (link.favicon_url || '') : '';
        document.getElementById('link-path').value = link ? (link.path || '') : '';
        modal.style.display = 'flex';
    }

    async function editLink(id) {
        try {
            const links = await LinkSync.getLinks();
            const link = (Array.isArray(links) ? links : []).find(l => l.id === id);
            if (link) openModal(link);
        } catch (err) {
            alert('Failed to load link details');
        }
    }

    function confirmDelete(id) {
        deleteTargetId = id;
        deleteModal.style.display = 'flex';
    }

    function closeModal() {
        modal.style.display = 'none';
        form.reset();
    }

    function closeDeleteModal() {
        deleteModal.style.display = 'none';
        deleteTargetId = null;
    }

    function openSaveCollectionModal() {
        const currentSearch = searchMode === 'query' ? queryInput.value.trim() : searchInput.value.trim();
        const isQueryMode = searchMode === 'query' && currentSearch;
        document.getElementById('save-collection-type').value = isQueryMode ? 'dynamic' : 'static';
        document.getElementById('save-collection-name').value = isQueryMode ? `Query: ${currentSearch}` : `Search: ${currentSearch}`;
        document.getElementById('save-collection-desc').value = '';
        document.getElementById('save-collection-public').checked = false;
        saveCollectionModal.style.display = 'flex';
    }

    function closeSaveCollectionModal() {
        saveCollectionModal.style.display = 'none';
        saveCollectionForm.reset();
    }

    document.getElementById('new-link-btn').addEventListener('click', () => openModal());
    document.getElementById('modal-close').addEventListener('click', closeModal);
    document.getElementById('cancel-btn').addEventListener('click', closeModal);
    document.getElementById('delete-cancel-btn').addEventListener('click', closeDeleteModal);
    document.getElementById('save-collection-btn').addEventListener('click', openSaveCollectionModal);
    document.getElementById('save-collection-modal-close').addEventListener('click', closeSaveCollectionModal);
    document.getElementById('save-collection-cancel-btn').addEventListener('click', closeSaveCollectionModal);

    modal.querySelector('.modal-overlay').addEventListener('click', closeModal);
    deleteModal.querySelector('.modal-overlay').addEventListener('click', closeDeleteModal);
    saveCollectionModal.querySelector('.modal-overlay').addEventListener('click', closeSaveCollectionModal);

    form.addEventListener('submit', async function(e) {
        e.preventDefault();
        const saveBtn = document.getElementById('save-btn');
        saveBtn.disabled = true;
        saveBtn.textContent = 'Saving...';

        const id = document.getElementById('link-id').value;
        const isEdit = id && id !== '' && id !== 'undefined';
        const tagsRaw = document.getElementById('link-tags').value;
        const data = {
            url: document.getElementById('link-url').value,
            title: document.getElementById('link-title').value,
            description: document.getElementById('link-description').value || null,
            notes: document.getElementById('link-notes').value || null,
            tags: tagsRaw ? tagsRaw.split(',').map(t => t.trim()).filter(t => t) : [],
            favicon_url: document.getElementById('link-favicon').value || null,
            path: document.getElementById('link-path').value || null,
        };

        try {
            if (isEdit) {
                await LinkSync.updateLink(id, data);
            } else {
                await LinkSync.createLink(data);
            }
            closeModal();
            loadLinks(searchMode === 'query' ? queryInput.value : searchInput.value);
        } catch (err) {
            alert('Failed to save link: ' + err.message);
        } finally {
            saveBtn.disabled = false;
            saveBtn.textContent = 'Save';
        }
    });

    saveCollectionForm.addEventListener('submit', async function(e) {
        e.preventDefault();
        const saveBtn = document.getElementById('save-collection-save-btn');
        saveBtn.disabled = true;
        saveBtn.textContent = 'Saving...';

        const name = document.getElementById('save-collection-name').value;
        const desc = document.getElementById('save-collection-desc').value || null;
        const type = document.getElementById('save-collection-type').value;
        const isPublic = document.getElementById('save-collection-public').checked;

        const data = {
            name,
            description: desc,
            query_type: type,
            is_public: isPublic,
        };

        if (type === 'dynamic') {
            const expression = searchMode === 'query' ? queryInput.value.trim() : searchInput.value.trim();
            data.query_expression = { expression };
        } else {
            data.link_ids = lastResults.map(l => l.id);
        }

        try {
            await LinkSync.createCollection(data);
            closeSaveCollectionModal();
            alert('Collection saved successfully');
        } catch (err) {
            alert('Failed to save collection: ' + err.message);
        } finally {
            saveBtn.disabled = false;
            saveBtn.textContent = 'Save';
        }
    });

    document.getElementById('confirm-delete-btn').addEventListener('click', async function() {
        if (!deleteTargetId) return;
        try {
            await LinkSync.deleteLink(deleteTargetId);
            closeDeleteModal();
            loadLinks(searchMode === 'query' ? queryInput.value : searchInput.value);
        } catch (err) {
            alert('Failed to delete link: ' + err.message);
        }
    });

    function doSearch() {
        const search = searchMode === 'query' ? queryInput.value : searchInput.value;
        loadLinks(search);
    }

    document.getElementById('search-btn').addEventListener('click', doSearch);
    searchInput.addEventListener('keypress', function(e) {
        if (e.key === 'Enter') doSearch();
    });
    queryInput.addEventListener('keypress', function(e) {
        if (e.key === 'Enter') doSearch();
    });

    const urlParams = new URLSearchParams(window.location.search);
    if (urlParams.get('action') === 'new') {
        openModal();
    }

    loadLinks();

    function escapeHtml(str) {
        if (!str) return '';
        const div = document.createElement('div');
        div.textContent = str;
        return div.innerHTML;
    }

    function formatDate(dateStr) {
        if (!dateStr) return '-';
        const d = new Date(dateStr);
        return d.toLocaleDateString();
    }
});